Jump to content


Photo
- - - - -

Ford F-350 suspension modification?


  • Please log in to reply
11 replies to this topic

#11 Machinebuilder

Machinebuilder

    Senior Member

  • Members
  • 481 posts
  • LocationEast Tennessee

Posted 21 June 2022 - 11:47 AM

With my limited knowledge of suspension design, the porposing is do to the damping not controlling the spring compression/rebound.

 

I know on my dual sport motorcycle If I increase the low speed rebound damping it will control the porposing better.

 

When you increase the spring rate by engaging the overload spring sooner the rebound will overpower the damping.

 

It's tough to get it all working well with widely varying loads.


  • 1

2021 F350 SCLB

FWC Grandby,

EBY Big Country Flatbed, Buckstop Outback front Bumper

Gabby (GSP), Sox (GSP/American Bulldog)

2011 F150 SCLB HDPP


#12 michelle_east_county

michelle_east_county

    Advanced Member

  • Registered (Tapatalk)
  • PipPipPip
  • 97 posts

Posted 21 June 2022 - 12:57 PM

Machine builder, agreed. Passing over a particular dip with the upper StableLoads it felt like the OEM shocks (truck has about 8000 miles) didn't have enough damping or dampening (resistance) during rebound (suspension extension) to control the quicker rate that it moved. The same dip after removal of the StableLoads at a similar speed felt smoother and more controlled. Any more weight would start to slow the effective spring rate down so much it'd be "floaty", like the overloaded trucks you see not yet riding on the axle bump stops. Per Fred Puhn's "How to Make Your Car Handle" I read about forty years ago, that Goldilocks zone of around 1.5 suspension cycles per second is hard to maintain with varying loads without air suspensions much more complex than typical sir bags, and shock valving even more complex. Even one-ton pickups have suspension designed to not be intolerably firm when empty, so a modest increase in overall spring rate via another leaf or two in the main leaf pack should be a good compromise.

Edited by michelle_east_county, 21 June 2022 - 09:26 PM.

  • 1




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users